Sequences amplified from five different flatfish species with primers whose sequences are based on conserved flanking sequences of the winter flounder pleurocidin. Abbreviations for species are as follows: AP, American plaice; GC, Glyptocephalus cynoglossus; HB, Atlantic halibut; WF, winter flounder; YT, yellowtail flounder. The positions of primers PL5′ and PL3′ are indicated by arrows. The following sequences correspond to the indicated manufactured peptides: AP1, peptide NRC-11; AP2, peptide NRC-12; AP3, peptide NRC-13; WF2, peptide NRC-4; YT2, peptide NRC-7; WF4, peptide NRC-6; GcSc4C5, peptide NRC-14; GC3.8, peptide NRC-17; GC3.2, peptide NRC-18; Wf3, peptide NRC-5; Hb26, peptide NRC-19; Hb18, peptide NRC-20; GcSc4B7, peptide NRC-15; WF1a, peptide NRC-2; Wf1 (NRC-1).